From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A5CBC10F0E for ; Tue, 9 Apr 2019 09:47:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2806720830 for ; Tue, 9 Apr 2019 09:47:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726826AbfDIJrH (ORCPT ); Tue, 9 Apr 2019 05:47:07 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:49182 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726001AbfDIJrG (ORCPT ); Tue, 9 Apr 2019 05:47:06 -0400 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 1DDF22820C8; Tue, 9 Apr 2019 10:47:05 +0100 (BST) Date: Tue, 9 Apr 2019 11:47:01 +0200 From: Boris Brezillon To: masonccyang@mxic.com.tw Cc: bbrezillon@kernel.org, computersforpeace@gmail.com, dwmw2@infradead.org, juliensu@mxic.com.tw, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, marek.vasut@gmail.com, miquel.raynal@bootlin.com, richard@nod.at, zhengxunli@mxic.com.tw Subject: Re: [PATCH] mtd: rawnand: Add Macronix NAND read retry and randomizer support Message-ID: <20190409114701.744c2c8c@collabora.com> In-Reply-To: References: <1554780172-23111-1-git-send-email-masonccyang@mxic.com.tw> <20190409090427.22de9917@collabora.com> Organization: Collabora X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 9 Apr 2019 17:35:39 +0800 masonccyang@mxic.com.tw wrote: > > > + > > > +static const struct kobj_attribute sysfs_mxic_nand = > > > + __ATTR(nand_random, S_IRUGO | S_IWUSR, > > > + mxic_nand_rand_type_show, > > > + mxic_nand_rand_type_store); > > > > No, we don't want to expose that through a sysfs file, especially since > > changing the randomizer config means making the NAND unreadable for > > those that have used it before the change. > > > > Our on-die randomizer is still readable from user after the function > is enabled. You mean the memory is still readable no matter the randomizer state. Not sure how that's possible, but okay. > This randomizer is just like a internal memory cell > reliability enhanced. Why don't you enable it by default then? > It could be enable at any time with OTP bit function and that's why > we patch it by sys-fs. Sorry, but that's not a good reason to expose that through sysfs.